To make sure, here are some tools which measures CPU utilization (as this concerns CPU usage)
The sar command
use "sar -u 3 10" (10 entries are displayed every 3 seconds)
Check the %iowait and %idle values

Run the top command
ps -eo pcpu,pid,user,args | sort -r -k1 | less

You can get a top down view of the process with the highest CPU munchers.